1. Field of the Invention
The present invention relates to a glass-run channel attached to a door sash for sealing the gap between a door and a glass of a car for reducing a sliding resistance of the glass.
2. Prior Art
A conventional glass-run channel will be described with reference to FIGS. 1 and 2.
The glass-run channel attached to a door sash for sealing the gap between the door and the glass comprises a body 60 having an opening which is in a U-shape in cross section and lips 71 and 72 which protrude from the both ends of the opening of the body 60 toward the center line of the body 60 through which a glass 30 slides.
The sliding resistance of the glass 30, namely, the resistance which the glass receives when it slides comprises a frictional resistance and a deformation resistance which are proportional to the repulsive force which occurs when the glass 30 pushes open the lips 71 and 72 of the glass-run channel. The deformation resistance is larger than the frictional resistance, which causes the problem for making the sliding resistance of the glass 30 large. That is caused by the fact that when the glass 30 pushes the lips 71 and 72 open as it moves as illustrated in FIG. 1, the push open length is small but the push open angle is large, i.e. the deformation amount (X+Y) per moving distance Z of the glass 30 is large. To cope with the problem, a lower hardness material is adopted by the lips 71 and 72 so as to reduce the repulsive force of the lips 71 and 72, which has however caused another problem that the function to guide and hold the glass 30 is deteriorated.